The present invention relates to the field of well stimulation; more particularly, the present invention relates to the field of well stimulation through the application of hydro-mechanically generated fluid pressure pulses.
The oilfield services industry has long recognized the benefit of reducing fluid pressure pulses in a well. The inducement of such pressure pulses may result in enhanced well cleaning, more efficient placement of chemicals, and improved production of desirable fluids. Experiments conducted by Wavefront Energy and Environmental Services, Inc. have shown that pressure pulses having certain characteristics, such as low frequencies, short rise times, and slow decay rates, are optimal for applications such as chemical placement in a well bore matrix and waterflood recovery. A number of tools can be used to generate varying pressure gradients downhole and could be used to generate fluid pressure pulses in a well. Many tools currently in use, however, are sized to fit within well casing or openhole wells and cannot pass through the narrower inner diameters of tubing such as coiled tubing. Moreover, many tools currently in use operate at typical mud motor speeds, rather than at the slower speeds that are more likely to result in optimal pressure pulses.